Phytoplankton

Dinoflagellates
(Phylum Pyrrophyta = Dinophyta) are perhaps the most charismatic of the
phytoplankton. Not only are they beautiful to look at under the
scope, they also have the most diverse types of life histories, ecological
niches and unique adaptations of all the phytoplankton. They have
two flagellae (which is their namesake), one that stays close to the
median (pictured above) and one that trails the cell like a rudder. Although
Dinoflagellates are grouped with the phytoplankton, some species are
unable to photosynthesize and instead are heterotrophic - able to directly
ingest food. Because they are fairly large cells, they are easily
visible in plankton samples and if the samples are fresh, you can even
observe their characteristic spinning movement. Like other phytoplankton,
Dinoflagellates go through bloom cycles when they are highly abundant
and these blooms can be toxic (commonly called red
tides), or bioluminescent.

Gonyaulax Page,
by Allison Arnold and Monica Draghici. This genus of dinoflagellates
has some species that are toxic and some that bioluminesce - overall
a fascinating group of organisms. Here are links to some of the components
of this great website: